1. Technical Field
The technology disclosed herein relates to a lens barrel equipped with an optical system.
2. Background Information
A lens barrel having a second group lens capable of retraction in relation to a first group lens has been proposed in the past (see Japanese Laid-Open Patent Application 2011-150132). Here, a second group lens supporting frame (corresponds to a retracting lens frame) that supports the second group lens is able to retract with respect to a support member that supports the first group lens. More specifically, a pressed protrusion of the second group lens supporting frame is pressed by a detachment control protrusion formed on an imaging element holder. Consequently, the orientation of the second group lens supporting frame changes from an imaging enabled orientation to a retracted orientation.
In prior art, the orientation of the second group lens supporting frame was changed from an imaging enabled orientation to a retracted orientation by pressing on the second group lens supporting frame with the detachment control protrusion of the imaging element holder. In this case, the detachment control protrusion has to be formed so that it extends in the optical axis direction on the imaging element holder. Therefore, there is the risk that the imaging element holder will end up being larger.
One possible way to solve this problem is to provide a cam mechanism between the second group lens supporting frame and a frame body disposed around the outer periphery of the second group lens supporting frame. In this technology, for example, the second group lens supporting frame can be changed from an imaging enabled orientation to a retracted orientation by forming a cam groove in the frame body, and guiding the above-mentioned pressed protrusion in this cam groove of the frame body. In this case, however, there is the risk that forming the cam groove will make the frame body thicker in the radial direction and make the lens barrel larger. Also, if the cam groove is formed without increasing the thickness in the radial direction, there is the risk of a decrease in strength.
The technology disclosed herein was conceived in light of the above problem, and it is an object of the present technology is to reduce the size of a lens barrel without sacrificing the strength of the lens barrel.